The owner of an apartment building on Lake Street sued by the city for pumping groundwater into the Calhoun-Isles lagoon asserts that the city approved its plans.

Lake and Knox LLC said in an answer to the city lawsuit that city reviewed and approved its building plans and specifications, which included included information about two permanent dewatering pumps each rated at 500 gallons per minute.

The city asserts that Lake and Knox obtained temporary permits to pump water for its construction site at 1800 W. Lake St., but that it is now pumping illegally on a permanent basis. The city, later joined by the Park Board, is suing to block the discharge and recover damages.

But lawyers for the apartment owner assert that the city expressly approved a storm drain permit, certificate of occupancy and building permit that involved permanent dewatering of the property.

Lake and Knox said it applied for a permanent Department of Natural Resources water use permit after conferring with the city. It applied in April, 2013, after construction was completed, according to state records, but the city asked the state to hold off on acting on the permit, according to Jack Gleason, a DNR area hydrologist. He said the need for a permanent permit didn't come to light until after the city inquired whether the building had one.

The owner's attorneys also deny the city's claim that a temporary water use permit was limited to lowering the water table at the construction site for excavating a foundation, insisting that the dewatering was to lower the water table in the vicinity of the property. The company also denied the city's assertion that the apartment's connection to the storm sewer system was only for drainage from the property's land and roof.

It admits that the pumping of water into the lagoon may thin the ice, but denied that the pumping impairs the lakes or the city's sewer. It said it has worked "diligently and steadfastly" with the city to address its concerns.

The proposal for what became 56 upscale apartments was controversial in surrounding neighborhoods before it was approved and constructed in 2011. The city and Park Board recently installed for the second straight winter a drainage pipe to carry discharged water from the nearby sewer across the lagoon ice to a point in Lake Calhoun. That was done in part to accommodate skiers participating in this weekend's City of Lake Loppet events on Isles, Calhoun and the lagoon between them. .

(A temporary 12-inch drainage pipe in the background is temporarily carrying the storm sewer discharge from the lagoon to Lake Calhoun to avoid further thinning of the ice in the lagoon)